Width = int(t.numinput("Cartesain Coordinates", "Enter Width",200, minval = 200, maxval = 400))
Height = int(t.numinput("Cartesain Coordinates", "Enter Height", 200, minval = 200, maxval = 400))
Grid = t.textinput("Cartesian Coordinates", "Would you like a grid?")

# Pen size, pen speed, and pen color
t.pensize(5)
t.speed(10)
t.pencolor("black")
# User width (x)

if Width == +Width:
    t.goto(+Width, 0)
    t.goto(-Width, 0)
elif Width == -Width:
    t.goto(-Width, 0)
    t.goto(+Width, 0)
t.goto(0, 0)

# User Height (y)
if Height == +Height:
    t.goto(0, +Height)
    t.goto(0, -Height)
elif Width == -Height:
    t.goto(0, -Height)
    t.goto(0, +Height)
t.goto(0, 0)
t.penup()



# Setting grid pen size, color and speed

t.pensize(1)
t.pencolor('Gray')
t.speed(4)

# Defualt value for numinputs (x)

Default_width_value = 200

# List of possible (x) values

Possible_width_value1 = 250
Possible_width_value2 = 300
Possible_width_value3 = 350
Max_width_value = 400

# Starting the grid
if Grid == 'No':
    t.goto(0, 0)
if Grid == 'Yes':
    Grid = True
    while True:

    # The Outter Square
    
    t.goto(-Width, +Height)
    t.pendown()
    t.goto(-Width, -Height)
    t.goto(+Width, -Height)
    t.goto(+Width, +Height)
    t.goto(-Width, +Height)
    
    # The Inner Lines For Width (x) portion of Grid
    # First Line
    
    t.goto(-Width, -Height)
    t.forward(50)
    t.pendown()
    t.left(90)
    t.forward(+Height)
    t.forward(+Height)
    
    # Second Line
    
    t.right(90)
    t.forward(50)
    t.right(90)
    t.backward(-Height)
    t.backward(-Height)
        

    # Third Line

    t.left(90)
    t.forward(50)
    t.left(90)
    t.forward(+Height)
    t.forward(+Height)

    # Fourth Line
    
    t.right(90)
    t.forward(50)
    t.right(90)
    t.backward(-Height)
    t.backward(-Height)

    # Fifth Line

    t.left(90)
    t.forward(50)
    t.left(90)
    t.forward(+Height)
    t.forward(+Height)

    # Sixth Line

    t.right(90)
    t.forward(50)
    t.right(90)
    t.backward(-Height)
    t.backward(-Height)

    # Seventh Line

    t.left(90)
    t.forward(50)
    t.left(90)
    t.forward(+Height)
    t.forward(+Height)
    

    if Width > Default_width_value < Possible_width_value1:

        # First Line

        t.right(90)
        t.forward(50)
        t.right(90)
        t.backward(-Height)
        t.backward(-Height)
        

        # Second Line

        t.left(90)
        t.forward(50)
        t.left(90)
        t.forward(+Height)
        t.forward(+Height)
    
    elif Width > Possible_width_value1 < Possible_width_value2:

        # Third Line

        t.right(90)
        t.forward(50)
        t.right(90)
        t.backward(-Height)
        t.backward(-Height)
    

        # Fourth Line

        t.left(90)
        t.forward(50)
        t.left(90)
        t.forward(+Height)
        t.forward(+Height)

    elif Width > Possible_width_value2 < Possible_width_value3:
    
        # Fifth Line
            
        t.right(90)
        t.forward(50)
        t.right(90)
        t.backward(-Height)
        t.backward(-Height)

        # Sixth Line
            
        t.left(90)
        t.forward(50)
        t.left(90)
        t.forward(+Height)
        t.forward(+Height)

    elif Width > Possible_width_value3 < Max_width_value:

        # Seventh Line

        t.right(90)
        t.forward(50)
        t.right(90)
        t.backward(-Height)
        t.backward(-Height)

        # Eighth Line

        t.left(90)
        t.forward(50)
        t.left(90)
        t.forward(+Height)
        t.forward(+Height)
    else:
        t.penup()
        t.goto(0, 0)

First id like to say that im very new to python

The issue is when creating a grid for a cartesian coordinate, i can get it to create the grid at the minval() but once i start increasing in increments of 50 till maxval() is where i have trouble. ive tried to put the if() in the while loop, which is where i found the problem, ive also tried it out side which is where it worked fine whilest increasing in incraments of 50 but the issue i had there was it would still try and draw part of the grid even if the user said no to the grid. Its for an assinment and i can only use whats in the turtle module. Any help is very much appreciated.